[ovs-dev] [PATCH] datapath: Fix checksum update for actions on UDP packets.
Jesse Gross
jesse at nicira.com
Tue Mar 6 22:55:41 UTC 2012
When modifying IP addresses or ports on a UDP packet we don't
correctly follow the rules for unchecksummed packets. This meant
that packets without a checksum can be given a incorrect new checksum
and packets with a checksum can become marked as being unchecksummed.
This fixes it to handle those requirements.
Bug #8937
Signed-off-by: Jesse Gross <jesse at nicira.com>
---
datapath/actions.c | 38 ++++++++++++++++++++++++++++++--------
1 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/datapath/actions.c b/datapath/actions.c
index 4b07603..6f6b82d 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -147,9 +147,17 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
*addr, new_addr, 1);
} else if (nh->protocol == IPPROTO_UDP) {
- if (likely(transport_len >= sizeof(struct udphdr)))
- inet_proto_csum_replace4(&udp_hdr(skb)->check, skb,
- *addr, new_addr, 1);
+ if (likely(transport_len >= sizeof(struct udphdr))) {
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (uh->check ||
+ get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
+ inet_proto_csum_replace4(&uh->check, skb,
+ *addr, new_addr, 1);
+ if (!uh->check)
+ uh->check = CSUM_MANGLED_0;
+ }
+ }
}
csum_replace4(&nh->check, *addr, new_addr);
@@ -199,8 +207,22 @@ static void set_tp_port(struct sk_buff *skb, __be16 *port,
skb_clear_rxhash(skb);
}
-static int set_udp_port(struct sk_buff *skb,
- const struct ovs_key_udp *udp_port_key)
+static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (uh->check && get_ip_summed(skb) != OVS_CSUM_PARTIAL) {
+ set_tp_port(skb, port, new_port, &uh->check);
+
+ if (!uh->check)
+ uh->check = CSUM_MANGLED_0;
+ } else {
+ *port = new_port;
+ skb_clear_rxhash(skb);
+ }
+}
+
+static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
{
struct udphdr *uh;
int err;
@@ -212,10 +234,10 @@ static int set_udp_port(struct sk_buff *skb,
uh = udp_hdr(skb);
if (udp_port_key->udp_src != uh->source)
- set_tp_port(skb, &uh->source, udp_port_key->udp_src, &uh->check);
+ set_udp_port(skb, &uh->source, udp_port_key->udp_src);
if (udp_port_key->udp_dst != uh->dest)
- set_tp_port(skb, &uh->dest, udp_port_key->udp_dst, &uh->check);
+ set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
return 0;
}
@@ -338,7 +360,7 @@ static int execute_set_action(struct sk_buff *skb,
break;
case OVS_KEY_ATTR_UDP:
- err = set_udp_port(skb, nla_data(nested_attr));
+ err = set_udp(skb, nla_data(nested_attr));
break;
}
--
1.7.5.4
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